On Tue, May 19, 2020 at 10:19:06PM +0200, Sebastian Andrzej Siewior wrote: > The radix-tree and idr preload mechanisms use preempt_disable() to protect > the complete operation between xxx_preload() and xxx_preload_end(). > > As the code inside the preempt disabled section acquires regular spinlocks, > which are converted to 'sleeping' spinlocks on a PREEMPT_RT kernel and > eventually calls into a memory allocator, this conflicts with the RT > semantics. > > Convert it to a local_lock which allows RT kernels to substitute them with > a real per CPU lock. On non RT kernels this maps to preempt_disable() as > before, but provides also lockdep coverage of the critical region. > No functional change. I don't seem to have a locallock.h in my tree. Where can I find more information about it? > +++ b/lib/radix-tree.c > @@ -20,6 +20,7 @@ > #include <linux/kernel.h> > #include <linux/kmemleak.h> > #include <linux/percpu.h> > +#include <linux/locallock.h> > #include <linux/preempt.h> /* in_interrupt() */ > #include <linux/radix-tree.h> > #include <linux/rcupdate.h>
